Environmental center. Cross between Heinz History Center, The Science Center and the Phipps. Discuss the past and present of Pittsburgh and offer solutions toward a future with cleaner air, water, etc. Different stations in the space could have wildlife learning (birds of the city, flora of Western PA, etc), a greenhouse to grow..."produce"...and could include spaces for the Green Building Alliance, Venture Outdoors and Grow Pittsburgh to have outposts or headquarters. The hope could also be a push toward sustainable energy production. (full disclosure, this was my wife's idea, as she is much smarter than me but didn't have the time to type it up. :) )